GPE-AGT shRNA纳米粒转染体系介导RNAi对SHR早期动脉粥样硬化病变的影响

目的 观察靶向AGT RNAi对高血压合并早期动脉粥样硬化病变的影响.方法 建立高血压合并动脉粥样硬化（atherosclerosis,AS）大鼠模型,尾静脉注射携带AGT shRNA GPE纳米复合物（shRNA）,每10天重复注射1次,连续9w,设SHR基础组（control）、空白对照组（blank）和阴性对照组（negative）.尾袖法测量大鼠尾动脉收缩压和心率.Real-time PCR检测肝脏AGT mRNA水平的表达,Western-blot法检测肝脏AGT蛋白水平的表达,ELISA法测定血AGT和AngⅡ的含量.HE染色及电镜观察大鼠颈动脉血管壁形态改变.全自动生化分析仪检测肝肾功能.结果 shRNA组肝脏AGTmRNA表达均较blank组、negative组下降,差异有统计学意义（P＜0.05）,肝脏AGT蛋白表达结果与mRNA表达变化相一致（P＜0.05）,血清AGT、AngⅡ的含量减少（P＜0.05）.shRNA组第3天,尾动脉压下降约（27＆#177;4） mmHg,与治疗前比差异有统计学意义（P＜0.05）,3d后尾动脉压下降缓慢,降压作用持续8d左右,最大降压幅度达（31＆#177;4）mmHg,注射后第11天血压开始回升.其余三组尾动脉压无下降.治疗前后各组大鼠心率均无明显变化.shRNA组光镜及电镜显示动脉粥样硬化性病变明显减轻.各组肝肾功能结果差异无统计学意义（P＞0.05）.结论 GPE-AGT shRNA纳米粒转染高血压合并AS病变大鼠模型后,平稳降压,改善了血管病变,从而延缓早期动脉粥样硬化病变的进展.

Effects of GPE-AGT nanoparticle shRNA transfection system mediated RNAi on early atherosclerotic lesion

Objective To investigate the effects of RNA interference targeting AGT on early atherosclerotic lesion in the hypertensive state. Methods Hypertension and atherosclerosis rats were treated with GPE nanoparticles carrying AGT shRNA. Systolic blood pressure and heart rate were measured for 2 consecutive weeks. Three days after treatment, the mRNA and protein expressions of AGT in the liver were measured by PCR and western blot assay, respectively. The blood levels of AGT and Ang II were determined by ELISA. H＆E staining and electron microscopy were performed. Results Three days after AGT shRNA treatment, the mRNA andprotein expressions of AGT in the liver were markedly reduced and the blood levels of AGT and Ang II dramatically decreased as compared to the remaining 3 groups （P〈0.05）. Three days after AGT shRNA treatment, the blood pressure was reduced by （ 27 ＋ 4 ） mmHg when compared with that at baseline （P 〈 0.05）. About 11 days after AGT shRNA treatment, the blood pressure began to increase. The blood pressures were unchanged in the remaining 3 groups. The atherosclerotic lesions under microsopy were markedly attenuated in AGT shRNA treated rats but the liver and kidney functions remained stable （P〉0.05） when compared with the remaining 3 groups. Conclusion Transfection with GPE nanoparticle carrying AGT shRNA can stably lower the blood pressure and delay the development of early atherosclerotic lesions in hypertension rats.